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# Help Me Understand This Equation

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What are the triangles? What is x, p and what does the h with the line through it mean?

Thank you.

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Well, without context, it's really impossible to tell what x and p mean. But h-bar is the Dirac constant, and the [math]\Delta[/math] signs mean "change in." So the change in x times the change in p is greater than or equal to the Dirac constant over 2.

I could hazard a guess that p is momentum, but it depends on what p has been defined to be in the context.

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That's Heisenberg's famous uncertainty principle. The triangle symbols mean uncertainty in. So the uncertainty in position multiplied by the uncertainty in momentum have to be larger than a constant- this means you can never 100% accurately predict the future.

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Okay, I'm close to getting it. I understand the meaning of the Heisenberg diddy, yet not the mathematics. Most of this makes sense to me except that I thought the

Dirac constant was expressed as h/2pi.

I flunked out of math class more than once.

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• 2 weeks later...
Most of this makes sense to me except that I thought the Dirac constant was expressed as h/2pi.

"h-bar" or the Dirac constant is h/2pi.

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